Abstract

ELECTRON TRANSFER REACTION BETWEEN PYRIDINIUM CHLOROCHROMATE (VI) AND METFORMIN, AN ANTIDIABETIC DRUG IN AQUEOUS ACID MEDIUM

J. Panda, A. K. Patnaik*, G. C. Pradhan and P. Mohanty

Abstract

The electron transfer reaction of metformin with pyridinium chlorochromate (PCC) has been studied spectrophometrically over the range 2.0 103[Metformin] 6.0, 0.05 [H+] 0.20, 293 T 313 K and I = 0.3mol dm-3 (NaClO4). The rate of the reaction is found to increase with increase in [H+] and [Metformin]. The activation parameters such as H≠ , S≠ and G≠ for electron transfer reaction are found to be 11.55 2.08 k J mol-1 and -212.3 6.78 J K-1 mol-1 and 74.8 k J mol-1 respectively. Positive value of G≠ and positive value of H≠, indicate that transition state is highly solvated while negative value of S≠ suggests the formation of the compact activated complex. The oxidation product was isolated and identified as metformin N-Oxide which was supported by FTIR and Mass Spectral analysis.

Keywords: Kinetics and mechanism, electron transfer, pyridinum chlorochromate, metformin.